The invention relates to an air bag module.
It is known that air bag modules can be installed in a motor vehicle in order to protect the passengers from injury in the event of the motor vehicle being involved in an accident. This is achieved with the assistance of an inflatable pillow, or air bag, which is automatically inflated by a gas generator.
These air bag modules are provided with a cover in the motor vehicle. The air bag module is thereby protected from damage which can jeopardise the functioning of the air bag module. Also, the cover can be adapted to suit the aesthetic layout of the motor vehicle interior.
In the case of known air bag modules, this cover is attached by means of rivets to a carrier on which the gas generator and the gas bag are also positioned.
In the assembly of the known air bag modules, the gas generator and the gas bag are attached to a box-like carrier. On the base of the carrier, there are nuts or screws which allow the air bag module to be connected to the motor vehicle. The cover is secured to the side walls of the box-like carrier by means of rivets. The cover is made of plastic whereas the box-like carrier is made from aluminium or steel.
The known means of securing the cover has numerous disadvantages in its mechanical properties and its assembly. The plastic cover is secured by rivets at certain points which can give rise to rips and tears of the gas bag at the connection points in the event of continual use of the connection points. In order to prevent any individual rivet from being used excessively, a very large number of rivets must be attached to the cover around the side walls. The installation of the known cover on the carrier is therefore extremely labour-intensive and several production units are needed for the installation.
Furthermore, the known method of installation makes it considerably difficult to re-use the cover and the carrier because the rivet connection cannot be undone without costly intervention. When separating the materials, it is necessary to neatly separate the rivets, the cover and the carrier.
Published International Application WO 94/25313 discloses an air bag module with a gas generator and a gas bag, with an open housing for the gas generator and the gas bag on its end walls, as well as with a housing cover. This air bag module has on opposite-facing sides, profiled sections to which recesses in the housing correspond, and into which the profiled sections can be inserted from an end wall. After insertion, the housing on the end walls is locked by cover caps, whereby the ends of the profiled sections are also simultaneously fixed.
This air bag module has the disadvantage that the entire cap must be inserted into the case from an end wall of the case making assembly more difficult and requiring more free space on the side of the case.
U.S. Pat. No. 5,263,739 discloses an air bag module in which a gas bag is secured in an open-topped box-like housing by means of a profile rod. This housing is pushed from an end wall into profile grooves of a gas generator housing. This air bag module has the disadvantage that compact components groups must be brought into a housing from the end wall.